150pcs M4x16mm Screws Hex Socket Cap 12.9 Steel Black Zinc Full Thread

150pcs M4x16mm Screws Hex Socket Cap 12.9 Steel Black Zinc Full Thread

• Electroplating Process + Oil-Free Design: Adopts high-quality electroplating technology with a smooth, dense surface free of greasy residues. No hand or tool staining during handling and installation, ensuring a clean and efficient construction process.
• 200+ Hours Salt Spray Test Certified: Complies with ISO 9227:2022 (Neutral Salt Spray/NSS) standard, with corrosion resistance exceeding 200 hours. No red rust on the surface, and white rust ratio ≤ 3%, easily adapting to harsh environments such as outdoor humidity and coastal high salinity.
• 12.9 Grade High-Strength Hardcore Quality: Meets 12.9 grade hardness standards, with tensile strength and shear resistance far superior to ordinary bolts. Capable of withstanding high-strength fastening requirements for heavy machinery and industrial supports.
• High-Precision Thread Engagement: Thread accuracy remains unaffected after electroplating, enabling smooth screwing without jamming. Features strong fastening force, no easy loosening or slipping, and is compatible with various nuts and connectors.
• Strict Quality Control Assurance: Each batch of products undergoes sampling inspection. Coating thickness, salt spray resistance, thread precision and hardness indicators all meet international standards, ensuring stable and reliable quality.